when stars are born, what sorts of gases do protostars/nebulas contain?

Question: when stars are born, what sorts of gases do protostars/nebulas contain?
- Keywords:
  chemistry,
  space,
  star
Asked by albertthesciguy to Nick on 13 Mar 2014.
- Nick Wright answered on 13 Mar 2014:
  
  That’s a good question! We believe that stars are born out of the gas that floats around in our Galaxy. This gas is mostly hydrogen, about 75%, because hydrogen is the most abundant element in the Universe. The second most abundant element is Helium, about 24% of gas is helium in the Universe. Its very fortunate that these are the most abundant gases because stars mostly burn hydrogen in their cores, but some also burn helium.

Question: when stars are born, what sorts of gases do protostars/nebulas contain?